Pump



Dec. 25, 1962 w. H. MASHINTER 3,070,030

PUMP

Filed July 24, 1958 6 Sheets-Sheet l i //A@&

Dec. 25, 1962 w. H. MASHINTER PUMP 6 Sheets-Sheet 2 Filed July 24, 1958 INVENTOR.

W. H. MASHINTER Dec. 25, 1962 6 Sheets-Sheet 3 Filed July 24, 1958 Dec. 25, 1962 w. H. MASHINTER PUMP 6 Sheets-Sheet 4 Filed July 24, 1958 mm QM QNN QM mm Em QM m QMN NW Q amiai whM NMN Dec. 25, 1962 I w, -M s 1 3,070,030

PUMP

Filed July 24, 1958 6 Sheets-Sheet 5 3,fl7,fliifl Patented Dec. 25, 1952 PUMP William H. Mashinter, Palatine, ill. Hills-McCanna Co, 400 Maple St, Carpentersviile, ill.) Filed July 24, 1953, Ser. No. 750,760 6 Claims. (Cl. 103-152) The present invention relates to a novel fluid pumping structure.

Positive displacement pumps presently commercially available may be generally classified according to capacity. For example, miniature pumps are generally considered to be those which deliver one gallon per hour or less and metering pumps are provided in various sizes adapted to deliver one-half gallon to approximately three hundred gallons per hour. High volume positive displacement pumps have been provided for delivering volumes at least as high as fifteen hundred gallons per hour, but in such heretofore proposed pumps accurate metering in a simple and economical manner is generally not available. Larger power pumps have also been provided. The present invention is concerned primarily with the high volume positive displacement class of pumps and the problems provided thereby but it is to be understood that many of the features of the invention disclosed herein may also be effectively incorporated in the other classes of pumps.

An important object of the present invention is to provide a novel relatively high volume pump structure capable of metering the fluid being pumped.

A further object of the present invention is to provide a novel high volume pumping structure which is of rela tively light weight and compact construction for a given capacity.

Another important object of the present invention is to provide a novel high volume pumping structure utilizing diaphragm pumping means, which structure is such that problems of cavitation are largely eliminated and the pumping structure is self-priming.

A more specific object of the present invention is to provide a novel pumping structure of the type mentioned in the preceding paragraph which is capable of pumping both liquid and gas or vapor.

Another object of the present invention is to provide a positive displacement pumping structure which may be readily adjusted instantly to vary the output thereof in a predetermined manner.

Still another object of the present invention is to provide a novel high volume positive displacement pumping structure which is constructed so that pumping means thereof at the discharge or fluid end of the pumping structure moves at a relatively low speed as compared with driving means of the pumping structure whereby to minimize problems such as cavitation, excessive wear and inefficient operation which accompany high speed operation of the pumping means.

A further object of the present invention is to provide a novel pumping structure of the above described type which is of economical construction and which is built so that various parts or subassemblies thereof may be readily repaired or replaced so as to facilitate more economical maintenance.

Another object of the present invention is to provide a novel high volume positive displacement pump of the above described type which is constructed so that no mechanical speed reducing means is required between relatively high speed driving means and low speed pumping means whereby the structure may be produced more economically and with reductions in size and weight.

Additional specific objects of the present invention are to provide a novel positive displacement pumping structure wherein leakage is substantially eliminated with the result that high pumping efliciencies are obtained, to provide a structure which may be readily adapted for handling substantially any fluid including corrosive as well as noncorrosive materials, and to provide a pumping structure that will not be injured by the passage of solid particles therethrough.

Still another important object of the present invention is to provide a novel pumping structure wherein pumping elements or diaphragm means are actuated by fluid under pressure provided by driver means, when drive means is of relatively light weight, economical and eflicient construction.

A more specific object of the present invention is to provide a novel fluid driver including reciprocable piston means actuated by rotary cam or wobble plate means on a rotary shaft, which driver is constructed so as to eliminate any need for heavy thrust bearings for the shaft.

Still another object of the present invention is to provide a novel fluid driver including reciprocable piston type pumping means, which driver is constructed so as to start pumping action when the piston means has zero velocity whereby to obtain a substantially shockless pumping action. a

A further object of the present invention is to provide a novel fluid driver of the above described type which is constructed so as to provide a substantially constant fluid flow or output.

Still another object of the present invention is to provide a novel fluid driver utilizing reciprocable piston pumping means, which driver is adjusted so that the output thereof may be varied in infinite increments and so that complete filling of pumping chamber means during each stroke of the piston means is obtained regardless of any adjustment for controlling the output whereby a substantially constant compression ratio and. more uniform and eflicient pumping action are obtained.

A more specific object of the present invention is to provide a novel fluid driver which is constructed so that when it is adjusted for reducing the fluid output, a portion of the fluid will be circulated within the driver so as to reduce agitation of the fluid and power losses.

Still another object of the present invention is to provide a novel driver including a plurality of reciprocable piston means, which driver is constructed so that a single element controls the output of all of the piston means whereby construction is simplified and made more economical and close manufacturing tolerances are not required since any error in the control element will be introduced into the output of all of the piston means.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings wherein- FIG. 1 is a side elevational view showing a pumping structure incorporating features of the present invention;

FIG. 2 is a front elevational view partially broken away for showing certain features of the pumping structure;

FIG. 3 is an enlarged sectional view showing fluid driver means constructed in accordance with features of the present invention and adapted to be installed in the pumping structure shown in FIGS. 1 and 2;

FIG. 4 is an enlarged fragmentary sectional view taken generally along line 4-4 in FIG. 1;

FIG. 5 is a cross sectional view on a reduced scale taken generally along line 5-5 in FIG. 3;

FIG. 6 is a fragmentary partial sectional view taken generally along line 6-6 in FIG. 3;

FIG. 7 is a fragmentary cross sectional view taken along line 7-7 in FIG. 6;

FIG. 8 is a perspective view showing a control ele- 3 ment of the fluid driver structure constructed in accordance with features of the present invention;

FIG. 9 is an exploded perspective view showing check valve means utilized in the apparatus of this invention;

FIG. 10 is a sectional view taken along line 10-10 in FIG. 11;

FIG. 11 is an enlarged sectional view taken along line 11l-11 in FIG. 1;

FIGS. 12 and 13 are similar enlarged fragmentary sectional views showing portions of the mechanism in different positions of operation;

FIG. 14 is a sectional view taken along line 1414 in FIG. 12;

FIG. 15 is a partially exploded perspective view of the portion of the mechanism shown in FIGS. 12-14;

FIG. 16 is a fragmentary sectional view similar to FIG. 11 but showing the elements in a different operative position;

FIG. 17 is a sectional view taken generally along line 1717 in FIG. 16;

FIG. 18 is a fragmentary sectional View taken along line 1818 in FIG. 17;

FIG. 19 is an exploded perspective view showing a valve structure utilized in the mechanism of this invention;

and

FIG. 20 is an enlarged fragmentary sectional view taken 1 along line 2tl2tl in FIG. 2.

Referring now more specifically to the drawings, wherein like parts are designated by the same numerals throughout the various figures, a pumping apparatus incorporating features of the present invention is shown generally in FIGS. 1 and 2. This apparatus comprises an upstanding frame 32 which provides a sump 0r reservoir 34 for actuating fluid or hydraulic oil which is circulated in the manner described in detail below. In order to provide sufficient power for enabling the pumping apparatus to deliver relatively high volumes of fluid without unduly increasing the size and weight of the apparatus, high speed fluid driver means 36 of relatively lightweight compact construction is mounted within the reservoir 34. A high speed electric motor 38 or other suitable prime mover is mounted on the frame 32 for actuating the driver 36. As indicated in FIGS. 1 and 3, an output shaft 40 of the motor is connected with a rotatable shaft 42 of the driver by suitable coupling means 44.

The driver 36 is adapted to deliver a continuous and substantially constant stream of fluid or oil under pressure. This stream of fluid is directed by conduits 46 and 4-8 to a diaphragm pump assembly 50 which is secured to a side of the frame means 32. As will be described more in detail below, the pump assembly 56 is adapted to be actuated by the fluid under pressure from the driver 36.

Referring particularly to FIGS. 1 and 3 through 8, the driver 36 which is, in effect, a relatively high speed pumping device will now be described in detail. The driver is provided with a main body member 52 having a central aperture 54 through which the rotatable shaft 42 extends. Cylindrical members 56 and 58 are respectively disposed against ends of the body member 52 and provide annular chambers as and 62 which are traversed by opposite end plates 64 and 66. The end plate 64 and the cylindrical member 56 are secured to the body member 52 by a plurality of screws 68. The end plate 66 and the cylindrical member 58 are similarly secured to the body member by a plurality of screws 70. Bearing assemblies 72 and 74 are mounted in suitable recesses provided in the end plates 64 and 66 respectively for rotatably supporting the shaft 42. It is to be noted that the structure does not include any heavy or substantial thrust bearing means for preventing axial shifting of the shaft 4-2 whereby the structure is simplified and made more economical. This feature is one result of other features described in detail below.

As shown in FIGS. 3 and 5, the body member 52 is provided with a plurality of piston accommodating bores or pump chambers 76 equally spaced about the axis of the body. Preferably there is an odd number and at least three of these bores and associated piston pumping means since such an arrangement facilitates phasing of the pumping action of the piston means associated with each bore so that the driver is capable of delivering a substantially continuous and constant stream of fluid. Opposed pistons 78 and Eli? are recip-rocably mounted in opposite end portions of each of the bores 7'6. Inlet openings or passageways 82 are provided in the body member 52 for each of the bores '76, which passageways are located midway between opposite ends of the bores 76 and communicate with the central bore or chamber 54 of the body member. Preferably the driver 36 is adapted to be mounted substantially completely submerged in the body of oil in the reservoir 34. Thus oil from the reservoir will flow into the driver and completely fill the chambers 6t 62 and 54 so that a supply of oil is available for entering the inlet ports 32. The opposite end assemblies of the driver are not fluid-tight so that oil may readily enter the driver chambers 60 and 62, and if desired openings, not shown, may be provided through the end plates 64 and 66 to facilitate entry of the oil into the driver. The body member 52 is provided with a plurality of outlet passageways 34 which extend radially from the bores 76 and are located so as to communicate with the bores midway between their opposite ends. The outer ends of the passageways $4 are respectively closed by plugs 86 and communicate with upwardly extending outlet ports 88.

The outlet ports are provided in a radially extending flange portion @ll of the body member 52 on which there is disposed a valve ring 92. The ring 92 is provided with a plurality of valve chambers 94 respectively communicating with the outlet ports 83. A flat centrally apertured valve seat member 96 is provided in each chamber 94 and a flat one way check valve 98 is also provided in each chamber for permitting fluid to flow from the outlet ports and through the valve chambers while preventing reverse flow of the fluid. Preferably springs 160 are provided for resiliently biasing the valve members 98 to closed positions. The outlets of the valve chambers 94 communicate with an annular manifold 102 provided in a ring member 104 mounted on top of the annular member 92. The annular members 194 and 92 are secured to the flange by means of a plurality of screws 1% indicated in FIG. 5. The manifold 162 has an outlet connected with the above mentioned pipe 4-6 which directs the fluid discharged from the driver to the pumping assembly 50.

In order to actuate the pairs of opposing pistons 78 and 80 in the various bores 76, cam or wobble plates 108 and 110 are keyed or otherwise fixed to opposite end portions of the shaft 42 within the chambers 64 and 62 respectively. Preferably lock rings 112 and 114 are provided between the cam plates and the adjacent bearing assemblies 72 and 74. In addition, hardened wear resisting annular facing elements 116 and 118 are preferably provided over the cam faces of the cam members 108 and lit) respectively. Bearing slide blocks 120 are respectively provided between the pistons 78 and the cam element 116, and similar bearing slide blocks 122 are provided between the ends of the pistons 80 and the cam element 118. It will be noted that each of these blocks has a spherical seat 124 for accommodating a rounded end 126 of an associated piston. These blocks are free to slide over their associated cam elements 116 or 118 as the cam elements are rotated by the shaft 42. Of course, relative sliding action will take place between the bearing blocks and the rounded ends of their associated pistons. The bearing blocks are maintained in assembled relationship between the cam elements and the pistons merely by the clamping pressure exerted through the pistons, which clamping pressure is provided by springs 128 between each pair of opposing pistons and by the fluid pressure created during a pumping operation.

It is important to note that the cam plates 1G8 and 110 are formed and connected to the shafts 42 so that their opposing annular cam faces provided by the elements 116 and 118 are disposed in planes inclined at identical but oppositely arranged acute angles with respect to the longitudinal axis of the shaft 42. In other words, the cam plates are oppositely disposed so that they will serve to actuate each pair of pistons 78 and St) in opposing relationship. For example, with the elements in the positions shown in FIG. 3, the pistons 78 and 80 at the lefthand side of the drawing are aligned with the lowermost portions of the cam surfaces so that both of these pistons are fully retracted or, in other words, these pistons have completed their suction strokes and are ready to begin their pumping strokes. It will be appreciated that as the cam plates are rotated, the op posing pistons will be axially shifted toward each other in unison so as to pump fluid which has been sucked into the bores 76 out through the associated discharge passageways and check valve chambers 94. It is important to note that during such a pumping operation, the axial thrusts exerted on the cam plates 108 and 11th will be equal and oppositely directed. As a result of the fact that both cam thrust loads are absorbed in the common shaft none of the thrust loads is transferred to the housing, thus obviating the necessity for thrust bearings.

In accordance with another important feature of the present invention, the driver is provided with a novel construction for controlling the pumping operation of the various pistons. More specifically, a rotary valve member 13d is mounted on the shaft 42 and secured against rotation relative to the shaft by an elongated key 132. However, the valve member 136 is adapted to be shifted axially of the shaft 42 in the manner described below for adjusting the output of the driver. As shown in FIGS. 3, 6 7 and 8, portions of the peripheral surface of the valve member 13h are cut away as at 134, 136, 138, Mt and 142 so as to provide fluid passageway means communicating with the chambers 60 and 62 within the driver and also adapted to communicate with the inlet ports 82 of the various pumping chambers or bores 76. The valve member is provided with a scroll 144 having a helical edge 1 36, which scroll is adapted to cover and seal the inlet ports 82 in a predetermined manner so as to control the pumping action.

The construction and arrangement of the valve memher 130 is correlated with the construction and arrangement of the cam plates 1% and 110 so that the inlet ports 82 are respectively uncovered by the scroll 144 during substantially the entire suction stroke of the piston means respectively associated with the various inlet ports 82. It is understood of course that the various inlet ports will be successively opened as the valve member 13%) rotates and the various piston means will be successively actuated through their suction strokes. However, the construction may be such that some overlap ping in the suction and pumping operation of successive piston means may be obtained for promoting the discharge of a continuous stream of fluid. It will be appreciated that since the inlet port for each pumping chamber is open during the entire suction stroke of its associated piston means, each pumping chamber will be completely filled with fluid or oil. This promotes more eflicient operation and enables the rate of discharge of the pumping mechanism of the driver to be accurately controlled. It is also important to note that when a port 82 is uncovered so as to terminate pumping of fluid through an associated outlet 84, fluid will be forced from the asso ciated chamber back into the cavity or reservoir between the valve member 130 and the member 52. The construction is such that when this occurs, the pistons in an adjacent chamber having an uncovered port 82 are starting their suction strokes. Thus, excess fluid spilled under pressure from one chamber serves to help fill an adjacent chamber and to prevent cavitation so as to insure complete filling of the chambers.

In accordance with a feature of the present invention, the driver is constructed so that a substantially shockless pumping action may be obtained. More specifically, the scroll 144 on the valve member 130 is positioned so that when, for example, the piston elements shown at the lefthand side of FIG. 3 have completed their suction strokes and have not yet started their compression strokes so that they are at a standstill, the scroll will accomplish complete closing and sealing of the inlet port 82 asso ciated with these pistons. Thus, when these pistons begin their pumping strokes, compression of the fluid begins immediately. In other words, the pumping action starts with the pistons at zero velocity so that any possibility of the occurrence of substantial shock is eliminated. Of course the structure is such that the remaining pistons function in an identical manner.

Referring again to the pistons 78 and 80 at the lefthand side of FIG. 3, it will be appreciated that as the cam plates continue to rotate from the positions shown, these pistons will be advanced toward each other so as to pump the fluid from the bore 76 and out through the associated check valve chamber 94. In accordance with the present invention, this pumping action will continue until the inlet port 82 is uncovered by the land or scroll 144 of the valve member 13%} whereby to relieve the pres sure within the chamber 76. More specifically, the pumping action will continue until the valve member has rotated sufficiently to cause either the helical edge 146 of the land or the narrow end 143 of the land to pass the inlet port 82 so as to uncover the port. It will be appreciated that the length of the pumping action may be varied even though the piston strokes remain constant by axially adjusting the valve member 13% .to change the time at which the helical land edge 146 passes the port 82. In the position shown in FIG. 3, the valve member 139 is substantially at its uppermost position so that the full circumferential extent of the land 144 will serve to close the port 82 and thereby provide for maximum pumping action and output. Upon lowering of the valve member 130 from the position shown, the helical edge of the land will be disposed so as to traverse the port 82 at any desired time to shorten the length of the pumping action and thereby reduce the output of the driver. It is to be appreciated that the structure just described permits substantially infinite variations in the output of the driver between zero output and maximum delivery. While the operation of the pistons at the lefthand side of FIG. 3 and the manner in which the pumping action thereof is controlled by the valve 130 has been described, it is to be understood that the remaining pistons of the driver are identically actuated and controlled.

In order to facilitate adjustment of the output of the driver, means is provided for quickly and easily axially adjusting the valve member 130 along the shaft 42. This means comprises a rod 150 which is axially slidably disposed within a central bore 152 formed in the lower end of the shaft 42. A transverse pin 154 is connected with the upper end of the rod 150. Opposite ends of the pin 154 extend through axially elongated slot means 156 formed in the shaft 42 and into complementary apertures provided in the valve member 130 for connecting the valve member with the rod 15%. Thus by axially adjusting the rod 159, axial adjustment of the valve member 130 is accomplished. The rod 150 rotates with the shaft 42 and therefore bearing means is provided at the lower end of the rod 150 to enable the rod to be connected with means for accomplishing adjustment thereof. This bearing means includes an inner race 158 fixed against axial movement relative to the rod by snap rings 169 and 16-2. An outer ball race 164- is suitably mounted within a ring 166. A bar 169 is pivotally connected to the ring 166 by a pin 170. In order to balance the forces involved, an identical bar, not shown, may be provided at the opposite side of the ring 166 from the bar 169 and pivotally connected thereto by a pin axially aligned with the pin 170. Additional pins 172 and 174 extend between and are secured to opposite ends of these bars. Stem means 176 which is welded or otherwise secured to the end plate 66 depends from the end plate at one side of the shaft 42 and has a horizontally elongated slot 178 adjacent its lower end for receiving the pin 17 2.

A flexible element 186 is connected with the pin 174 at the opposite ends of the bars from the pivot pin 172, which flexible element extends upwardly through passageways provided in the main body member 52, the cylindrical members 56 and 58 and the opposite end plates 64 and 66 of the driver. An upper end portion of the flexible element 180 is wrapped around a small drum 182, see FIG. 4, which drum is pinned or otherwise fixed to a shaft 184. The shaft is rotatably supported by a bushing 186 mounted in a suitable aperture provided in a Wall of the frame means 32 of the apparatus. A hand knob 188 is fixed to an outer end portion of the shaft 184 to permit turning of the shaft and raising or lowering of the flexible element 186. A nut member 1% is threaded onto the outer end of the shaft in such a manner that the frame wall 32 and the bushing 186 are clamped between the pulley or drum 182 and the knob 18% with a force which provides sufiicient frictional resistance to rotation of the shaft 184 to prevent accidental or unauthorized rotation of the shaft. It will be appreciated that upon rotation of the hand knob 188 in a direction which causes raising of the flexible element 180, the bar 169 will be raised so as to raise the rod 156 and thus the valve member 13%.. Upon opposite rotation of the hand knob 18%, the bar 169 and thus the valve member 136 are lowered. In order to insure lowering of the valve member when the hand knob 168 is turned in the appropriate direction, a spring 192 is compressed between the lower end of the shaft 42 and the bearing race 158.

It will be appreciated that during a pumping operation the bearing pressures between the mating surfaces of the pistons and the bearing blocks 120 and 122 and between the blocks and the cam elements 116 and 118 will be very high. In order to prevent undue wear of the mating bearing surfaces, the pistons and the bearing blocks are formed in a manner which insures lubrication of the surfaces after each pumping stroke of the pistons. More specifically, the pistons 78 and 80 are respectively provided with relatively large passageways 194 and 1% which extend axially from the counterbores which receive opposite ends of the springs 12%. The passageways 194 and 196 respectively merge with restricted orifices 198 and 200 which open centrally of the rounded ends of the pistons and communicate with enlarged passageways or chambers 292 and 204 in the bearing blocks 120 and 122. These last mentioned passageways or chambers merge with restricted orifices 206 and 208 formed centrally in the bearing blocks 126 and 122, which orifices in turn communicate with relatively large diameter recesses or chambers 210 and 212 which open at the cam engaging ends of the bearing blocks.

During a pumping stroke of the pistons, the pistons are forced against the bearing blocks and the bearing blocks are in turn forced against the cam elements 116 and 118 with suflicient force to prevent fluid or oil from leaking between the mating surfaces of these elements. At the same time, fluid is forced under high pressure and in a slightly compressed state through the passageways and restricted orifices in the ends of the pistons into the chambers 202216 and 204-212. As long as the pumping pressure is maintained the fluid will remain trapped and in a compressed state in these chambers in the bearing blocks. When the pumping pressure is relieved by the opening of the outlet port 82, the forces clamping the pistons against the bearing blocks and the bearing blocks against the cam elements are also largely relieved. The fluid or oil under pressure and in a compressed state in the chambers in the bearing blocks tends to flow back toward the passageways 194 and 196 in the pistons but such flow is retarded by the restricted orifices 198 and 200 and 266 and 268. As a result of these restrictions to such reverse flow and of the fact that the pressure between these various bearing surfaces is relieved, the fluid and the pressure in the chambers in the bearing blocks is forced out between the mating surfaces of the pistons and the bearing blocks and between the mating surfaces of the bearing blocks and the cam elements 116 and 118 so as to lubricate these surfaces. As will be understood, this lubricating action takes place at the end of each pumping stroke of the pistons so that constant lubrication of these mating surfaces is continuously insured.

Referring particularly to FIGS. -1, 2 and 9 through 20, the pumping assembly 56 will now be described in detail. The pumping assembly '56 comprises a main housing 216 which provides a reservoir for fluid or oil delivered from the driver. The housing 216 is closed by a removable cover 218, and pump heads 22% and 222 are mounted in oppositely disposed relationship in opposite side walls of the housing 216. As shown best in FIG. ll, the pump head 22%) is provided with an inner end plate 224 defining an inner pressure chamber 226, and an outer end plate 228 defining an outer pressure chamber 230, and an intermediate ring 232. A first flexible diaphragm 234 is peripherally clamped between the ring 232 and the inner end plate 224 and a second flexible diaphragm 236 is peripherally clamped between the ring and the outer end plate 228. These elements of the pumping head 220 are secured together and to the side wall of the housing 216 by a plurality of annularly spaced screws 238 shown in FIG. 1. It will be noted that a chamber 246 is provided between the diaphragms 234 and 236 which chamber is completely filled with a fluid or fluidized solid sufficiently liquid, or a true liquid which may be introduced upon removal of a filling plug 237 so that the outer diaphragm 236 will respond positively to any movement of the inner diaphragm 234.

A passageway 242 is provided in the end plate 224 for directing actuating fluid to and from the chamber 226 in the manner described in detail below so that the diaphragm 234 is alternately forced toward the left, as viewed in FIG. 11, and then permitted to return to the right. An inlet passageway 244 is provided in the end plate 22% for communicating with the pumping chamber 236, which inlet passageway is adapted to be connected with a supply conduit or fitting 246 which is connected to any suitable source of fluid to be pumped, not shown. Substantially identical check valve assemblies 248 and 256 are connected in series between the inlet passageway 244 and the supply conduit 246 for permitting fluid to flow into the inlet passageway 244 during a suction stroke of the diaphragm 236 and for preventing reverse flow of the fluid through the port or pasageway 244. An outlet passageway 252 is formed in the end plate 228. The outlet passage 252 is connected with a discharge manifold 254 through series connected one way check valve assemblies 256 and 258 and a suitable fitting 260. It will be appreciated that when the diaphragm 234 is moved toward the right as viewed in FIG. ll, there will be a tendency to create a vacuum in the chamber 240 and this causes the diaphragm 236 to move in unison with the diaphragm 234. This, in effect, expands the chamber 230 so that fluid is drawn past the check valve assemblies 248 and 251i and into the chamber through the inlet passageway 244. During the suction stroke of the diaphragrns, the valve element of the check valve assembly 256 engages its associated valve seat to prevent reverse flow of fluid from the manifold 254 and at the same time the valve element of the valve assembly 258 functions in a similar manner. Thus, if one of the valve elements of one of the valve assemblies should fail to function properly for any reason such as the deposit of foreign material on its asociated valve seat, the other valve assembly would insure continued proper operation of the pumping apparatus. As will be understood, after completion of the suction stroke, the diaphragms will be forced toward the left as viewed in FIG. 11 so as to pump the fluid from the chamber 230 into the manifold 254.

The pump head 222 is substantially identical to and functions in the same manner as the pump head 220. More specifically, the pump head 222 is provided with inner and outer end plates 262 and 264 which define pressure and pumpin chambers 266 and 268 respectively. An intermediate ring member 276 is clamped between the opposite end plates, and inner and outer diaphragms 2'72 and 274 are secured between the opposite sides of the ring member and the inner and outer end plates. Suitable fluid or liquid material is introduced between the diaphragms upon removal of the filling plug 275. A fluid passageway 276 is provided through the end plate 262 for communicating with the pressure chamber 266, and inlet and outlet passageways 278 and 280 are provided in the outer end plate 264. The inlet passageway 273 communicates with series connected check valve assemblies 282 and 23 which in turn are connected with a supply conduit or fitting 286. The outlet passageway 28% is connected with check valve assemblies 238 and 2% which in turn communicate with a fitting 292 connected with the manifold 254. As indicated in FIG. 2, the supply conduit or fitting members 246 and 286 may be interconnected to a common source of fluid by conduits 2% and 2%. The manifold 254 may be connected with a conduit 238 which extends to any suitable point of discharge.

In accordance with an important feature of the present invention, the pump assembly 5'0 is provided with means for directing fluid under pressure from the driver 36 to the pump heads 22% and 222 alternately and in a manner which enables the pump heads 224 and 222 to combine together to deliver a substantially continuous discharge of fluid. As was indicated above, the pump heads 22d and 222 are also actuated so that they are self-priming. More specifically, fluid from the driver 36 flows through the conduits 46 and 48 and into a manifold 3% through an inlet port 3&2. The manifold is provided with outlet ports 3% and 3% which respectively communicate with inlet ports 308 and 316 of mechanically interconnected switch valve assemblies 312 and 314. As shown best in FIGS. 11 and 16-19, the switch valve assembly 3i2 includes a body member 316 secured beneath the manifold 35th and between a frame member or plate 313 secured to and depending from the manifold 301') and the end plate 224- of the pump head 220. A transverse bore 329 is provided in the body member 316 for receiving a rotatable valve member 322. The inlet passageway 393 communicates with the bore 320, and a passageway 324 is provided in the valve body for establishing communication between the bore 320 and the passageway 242 of the pump head 22!). An outlet passageway 326 is provided for directing fluid from the bore 320 to the interior of the housing or reservoir 216. Another passageway 328 formed in the valve body is closed by a plug 33% and it will be appreciated that this passageway facilitates drilling of a portion of the inlet passageway 368. Passageway means 332 extends between the passageways 308 and 328 and around the central bore are so as to equalize the fluid pressure on opposite sides of the valve member 322 where-by manipulation or rotation of valve member 322 is facilitated.

The cylindrical valve member 322 is formed with a circumferentially extending recess or slot 334 having a concave bottom surface. This slot is formed and located so that it is adapted selectively to establish communication between the ports 3% and 324 when the valve member is in one position and between ports 324 and 326 when the valve member is in a second position. Peripheral sections 336 and 338 of the valve member at opposite ends of the slot 334 are adapted selectively to block the inlet port and the outlet port 326. The valve member 322 is provided with a second slot 340 substantially identical to but oppositely arranged from the slot 334. An aperture 342 is provided between the slots 334 and 348. With this arrangement it will be appreciated that the pressure of fluid in the slots 334 and 34 will be equalized so as to eliminate substantial radial thrust on the valve member which might resist free and easy rotation of the valve member. As shown in the drawings, the structure is such that when the valve member 322 is in the position shown in FIG. 11, the inlet port ass is blocked and the outlet port 326 is connected with the pressure chamber of the pump head 22s so that the fluid under pressure is exhausted therefrom and the diaphragms of the pump head 22% may be retracted or moved through their suction strokes. However, when the valve member 322 is shifted to the position shown in HS. 16, the outlet port 326 is blocked and inlet port 3% is connected with the pump head 220 so that fluid under pressure is directed into the pump head for actuatin the diaphragms through a pressure or pumping stroke.

The valve assembly 31 is mounted between the end plate 262 of the pump head 222 and a plate or frame member Edd depending from the manifold 3th and this valve assembly is substantially identical to the valve assembly 3&2. Thus the valve assembly 314 includes a body member in which the above mentioned inlet passageway 31%" is formed for communicating with a central transverse bore 348 in which a rotary valve member 35% is disposed. Pressure balancing passageway means and 354 are provided in the body member 34s as are passageways 3% and which respectively communicate with the pump head 2.22 and with the interior of the reservoir or housing 216. The cylindrical valve member 35% is identical to the valve member 322 and thus is provided with oppositely disposed slots 36b and 362 between peripheral sections and 356 which are selectively adapted to close the ports 31% and 358. An aperture 368 establishes communication between the slots and 362.

The valve member is operated in substantially the same manner as the valve member 322 for controlling reciprocable movement of the diaphragm means of the pump head 222. However it is important to note that the valve member 35% is operated oppositely from the valve member 322 so that when, for example, the valve member is disposed for connecting the pump head 222 with the inlet or pressure port 31%, the valve member 322 is disposed for connecting the pump head 22% with the exhaust port. Thus when the diaphragm means of the pump head 2.22 are being actuated through their pressure or pumping strokes, the diaphragm means of the pump head 225 are being actuated through their suction strokes and vice versa.

in accordance with an important feature of the present invention, the pump assembly 51"; is provided with control or feedback means for actuating the switch valve members 322 and 35:? only after the diaphragm means of the pump head 22% and 222 have completed a full stroke of predeterm ned length. More specifically, the construction is such that the length of the diaphragm movement in both of the pumping heads is always constant regardless of the desired output of the pumping assembly, variations in the output of the pumping assembly being accomplished by varying the rate of delivery of the fluid from the driver as so as to vary the rate of movement of the diaphragrns. One advantage of this feature is that during each cycle of operation, the diaphragm means of each of the pump heads will move through a suction stroke of maximum length so as to insure complete filling of the pumping chamber and through a pumping stroke of maximum length so as to accomplish pumping of uniform volumes of fluid, thus insuring constant compression at any pumping capacity. This not only enables the pumping apparatus of the present invention to deliver high volumes of relatively accurately metered fluid, but also to handle either liquids or gas so that the apparatus is self-priming.

In accordance with the present invention, the control or feedback means comprises a pair of rods 37% and 372 disposed in axial alignment and respectiveiy having opposite ends interconnected with the diaphragms 234 and 272 and having adjacent ends disposed between and connected with opposite end portions of links 374 and 376, see FIGS. ll-l6. While various suitable means may be provided for connecting the rods with the diaphragms, the rod 374} is provided with a threaded end portion turned into an internally threaded stud 37?. The stud 378 extends through central apertures in the diaphragm 234 and a pair of rigid plates and disposed at opposite sides or" the diaphragm 234 for distributing stresses over a relatively large area of the diaphragm and also assures the fact that diaphragm displacement is more piston-like in accentuating the use of the effective diaphragm. The stud member 372; is also externally threaded and a nut member is applied thereto for cooperating with the head portion of the stud member firmly to clamp the diaphragm between the plate members 331 and 382. The rod 372 is similarly connected to the diaphragm 272 by means of complementary stud and nut members 336 and 3% which clamp plate members 3%6- and against opposite sides of the diaphragm 272. The rods 374i and 37 are respec ively adapted to slide through bushings and 3% provided in the end walls 224 and 262 of the pump heads.

The adjacent or inner ends of the rods 37% and 372 are respectively connected with the links 374 and 376 by pins 398 and The pin 3% extes through slots :42 and 444 provided in the links and the pin 4% extends through similar slots 4'66 and The opposite or outer ends of these slots are located so that when the pins and 4% engage the outer ends of the slots the assembly including the rods and the links provides a positive connection between the diaphragm means of the pump heads 22% and 222 whereby these diaphragm means will move in unison.

A toggle mechanism is connected with the links 374 and 376 and with the rotary valve members 322 and 354) for successively actuating the valve members in opposite direction after the links 374 and 376 have been moved to predetermined positions in response to movements of the diaphragm means of the pumping heads. This toggle mechanism comprises a lever 416) which is pivotally mounted by a pin 412 extending through an intermediate portion thereof to side frame members and 4116 secured to opposite side edges of the depending plate members 318 and 344. The lower end of the lever 410 is provided with a reduced diameter stem 41% which is assembled by means of a slip connection with a tubular socket 424 pivotally connected between the links 374 and 376 by pins 422 and 424. This arrangement enables the toggle mechanism to be easily connected with the links 374 and 376 since it is merely necessary to slip the stem 418 into the socket member 424. It will be appreciated that as the links 374 and 3376 move back and forth with the diaphragm assemblies of the pump heads 220 and 222, the lever 41th will be oscillated about the pivot pin 412.

The upper end of the lever 414 extends between leg portions 426 and 428 of a toggle member 439 which includes a transverse top section 4312 integrally joining the leg portions 426 and 428. The toggle member 434 is pivotally connected to the side frame members 414 and 416 by screws 434 and 436 threaded into tapped apertures in the side frame members and having reduced diameter stub shaft portions 438 and 444 projecting into complementary apertures in the leg portions 426 and 428 of the toggle member. It is to be noted that the axis of the pivot pin 412 of the lever 410 is in the same vertical plane as the common axi of the stub shafts 438 and 4,40. The upper end of the lever 410 is pivotally connected to a bifurcated member 442 by a pin 444 having an axis oilset upwardly from the common axis of the stub shafts 438 and 440. A spring 446 is compressed between the bifurcated member 442 and the top section 432 of the toggle member 430. The toggle member 434 is connected to the rotary valve members 322 and 350 respectively by links 448 and 451 The links 448 and 450 are respectively connected with the toggle member by suitable pin means 452 and 454. These links are respectively eccentrically pivotally connected to the rotary valve members by suitable pins 456 and 458 located in the manner shown in FIGS. 11, 16, l7 and 18.

The control and feedback mechanism functions to actuate the switch valve assemblies 312 and 314 in the following manner. Starting, for example, with the various parts of the apparatus in the positions shown in FIG. ll, the pumping and suction strokes of the pump heads 22% and 222 respectively have just been completed and the valve members have just been shifted so as to start the pumping stroke of the pump head 222 and the suction stroke of the pump head 224). As the fluid under pressure from the driver flows into the chamber 266 of the pump head 222 and forces the diaphragm means of this pump head toward the right as viewed in FIG. 11, the rods 376 and 372 and the connecting links 374 and 376 serve to pull the diaphragm means of the pump head 224 toward the right in unison with the diaphragm means of the pump head 222. Furthermore, as the links 374 and 376 move toward the right as viewed in FIG. 11, the lever 410 is pivoted in a counterclockwise direction. The arrangement of the axes of the pivot pins 412 and 444 and of the pivot shafts 438 and 444 is such that the toggle member 430 remains stationary until the pivot pin 444 reaches a dead center position substantially in vertical alignment with the axes of the shafts 438 and 44d and the pin 412.

The arrangement is such that the pin 444 reaches this dead center position only after the diaphragm means of the pump head 222 has substantially completed the pumping stroke of predetermined length. Then, as the pin 444 passes the dead center position, the spring 446 or" the toggle mechanism functions to snap the toggle member 43!} substantially instantaneously from the position shown in FIGS. .11 and 13 to the position shown in FIG. 16. This action, of course, turns the valve members from the positions shown in FIG. 11 to the positions shown in FIG. 16 so as to reverse the flow of the driving fluid to the pump heads and reverse the direction of operation of the diaphragm means of the pump heads. It is to be noted that since the switching of the valves takes place at a high speed and since the pumping chambers of the pump heads 220 and 222 are always completely filled with fluid as a result of the full length strokes of the diaphragm means, the pumping action of each of the pump heads 220 and 222 will begin substantially instantaneously after the completion of the pumping action of the other pump head so that the two pump heads combine to produce a substantially continuous output.

As indicated above, the toggle member 436 is snapped to and from the positions shown in FIGS. 11 and 16 against the stops provided by the plates 313 and 344 at a high speed. In order to prevent undue shock to the toggle mechanism and also substantially to reduce operating noises caused by engagement of the toggle member with the stops, means is provided for cushioning the engagement of the toggle member against the stops. More specifically, the toggle member is provided with beveled surfaces 460 and 462 which are substantially flat and which are adapted to mate with the flat surfaces of the plate members 318 and 344-. In addition the oil or the like within the housing 216 is maintained at a level above the toggle member 430 and this is accomplished by providing a drain aperture 464, see FIG. 11, above the toggle member, which drain aperture establishes communication between the housing 216 and the reservoir within the frame 32. It will be appreciated that as the toggle member 43% is snapped toward one of the plate members, the oil will be squeezed between the plate member and the cooperating bevel surface of the toggle member to provide the above mentioned cushioning effect.

While the diaphragm means of the pump heads 220 and 222 are actuated in a manner so as to discharge a pre determined volume of fluid during each pumping stroke, it is obvious that the check valves in the various check valve assemblies connected with the inlets and outlets of the pumping heads must be adapted. accurately and reliably to control the flow of fluid through their associated passageways in order to enable the pumping apparatus to discharge a metered quantity of fluid. It has been found that valves such as conventional ball check valves frequently do not provide satisfactory results since ball check valves will chatter under many operating conditions and this undesirable characteristic is aggravated when a pair of the check valves are to be connected in series. It has been found that check valve means constructed as shown in FIG. 11 and as shown more in detail in FIGS. 9 and 10 provide superior results since the valve elements are quick acting and do not chatter. Since all of the valve assemblies associated with the pump heads 22(3 and 222 are substantially identical, only the assembly 148, shown in FIGS. 9, 10 and 11 will be described in detail. This valve assembly comprises a pair of complementary rings or body members 464 and 466. The body member 464 is provided with an aperture 468 adapted to mate with the port 244 of the pump head 220, and this body member also includes a chamber or counterbore 47b for accommodating a valve member 472. The' body member 4% has a passageway 474- therethrough and an upstanding annular shoulder 476 adapted to extend into the chamber d'itl. The shoulder 476 provides a flat annular valve seat 473 of considerable radial width. It is important to note that the valve member 472 is in the form of a relatively thin flat disc having a flat face adapted to engage the flat valve seat 478 for closing the valve opening. The diameter of the disc 472 is similar to the diameter of the valve chamber or bore 470 so that the walls of the bore will maintain the disc in general alignment with the valve seat 478 while at the same time the disc is sufliciently smaller than the diameter of the chamber so that the disc may move freely within the chamber. It is also important to note that the valve member or disc 472 is provided with a plurality of circumferentially spaced notches 480 which provide passageways permitting the fluid to flow around the valve memher when the valve member is raised from the seat.

The pumping apparatus is provided with relief valve means 482 which is shown in FIG. 20 for relieving pressure of the fluid delivered from the driver in the event such pressure exceeds a predetermined value for any reason. The relief valve means has a body member 484 which is connected to a suitable port in the manifold 33% by pipe means 486 as indicated in FIGS. 1, 2 and 20'. An inlet passageway 488 of the relief valve body member communicates with a counterbore 490 in which a valve member is axially slidable. A fiat annular valve seat 49 3 is provided between the passageway 488 and the counterbore 4% for cooperation with a flat end 4% of the valve member. The valve member is normally maintained against the valve seat by means of a compression spring 498 disposed in a further enlarged counterbore dbl) in the valve body member. An adjustable plug 5% is threaded into an end portion of the counterbore 5% for supporting the compression spring 498. The force which the spring exerts against the valve member 45 2 and thus the fluid pressure which is required to shift the valve member to open the valve may be adjusted by turning the plug 517?... An aperture 504 is provided through the plug 5% to permit any fluid which may leak into the counterbore 500 to escape. The relief valve is provided with a plurality of radially extending outlet passageways 5% which communicate with the counterbore 490. These passageways are axially spaced from the valve seat 494 so that the structure provides a resiliently expandable reservoir and any momentary overloads which may shift the valve 490 slightly from the valve seat will not cause opening of the relief valve. More specifically, during each operation of the switch valve means there is a very small fraction of a. second when the switch valve means substantially blocks both of the passageways 3% and 310. During this time the driver delivers a small volume of fluid or liquid which causes the valve 4-92 to be momentarily depressed. This substantially eliminates hydraulic shocks to which the system would be subjected in the absence of the shock absorbing and relief valve. When a more sustained undesirable overload is encountered, the valve member 4-92. is shifted sufficiently to uncover the radial outlet passageways 506 to relieve the pressure. It will be appreciated that as long as the excessive pressure acts against the flat or piston-like end 496 of the valve member 492, the valve member will be maintained in the open position. It is further to be noted that since the outlet passageways 506 are individually relatively small in diameter and thus their openings extend for only short distances axially of the bore 4%, the discharge ports 5% will be substantially fully opened very quickly when the undesirable overload is encountered. Preferably the discharge passageways 506 are formed so that the entire volume of fluid delivered from the driver 36 may be readily passed through the relief valve.

A brief resume of the operation of the apparatus of this invention is as follows. To initiate a pumping operation, the prime mover, see FIG. 1, or electric motor 38 is energized and the control knob 183, see FIG. 4, associated with the driver is adjusted so as to adjust the output of the driver 3t? in the manner described above. If desired the control knob 188 may be calibrated so as to cooperate with an indicator plate 508 secured to the frame of the apparatus to indicate to the operator the output for which the driver has been adjusted. The fluid or oil which flows in a substantially continuous uniform stream from the driver is directed to the manifold 360 of the pumping assembly 50 and from the manifold to the switch valves 312 and 314. Then the fluid is directed alternately through the switch valves 312 and 314-, see FIGS. 2, 11 and 16, to the pump heads 2.20 and 222 alternately to actuate the diaphragm means of these pump heads. As indicated above, the control and toggle mechanism of the pumping assembly functions to operate the switch valves in a manner which results in the diaphragm means reciprocating in the diagram means reciprocating with constant length strokes. it will be appreciated that the flexible diaphragms may be made from any suitable material. More specifically, the outer diaphragms 236 and 274, see FIG. 11, may be made from various materials which are especially suitable for use with particular materials to be pumped. For example, these diaphragms may be formed from rubber for pumping many materials or the diaphragms may be faced with a chemically inert substance such as tetra-fluoropolyethylene so that the apparatus is especially adapted for handling many corrosive materials. It is also to be noted that the pumping means may function without injury even though solid particles should enter the pumping chambers since the outer diaphragms may easily form themselves about such solid particles without injury.

From the above description it will also be noted that the apparatus in its entirety is formed in a manner which facilitates economical construction and maintenance. For example, the pump heads 229 and 222, see FIG. 11, may be easily removed and replaced as units. The same is true of a unit which is made up of the manifold 300, the switch valves and the toggle mechanism.

While the preferred embodiment of the present inven tion has been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. A fluid pumping apparatus comprising housing means providing a fluid reservoir, first and second substantially axially aligned and oppositely disposed pump head means on said housing means and respectively including first and second reciprocable flexible diaphragm pumping means, each of said diaphgram means including inner and outer axially spaced flexible diaphragms defining a sealed chamber therebetween substantially completely filled with a fluid so that the diaphragms will move in unison, a relatively high speed fluid driver disposed in said fluid reservoir adjacent said pump head means for delivering a stream of actuating fluid under pressure to said pump head means for actuating said diaphragm pumping means, said driver including pumping chamber means within said fluid reservoir and communicating with the fluid reservoir and opposing piston means in said chamber means for pumping fluid therefrom, said driver including a driven rotatable shaft and a pair of opposed means thereon for actuating said opposed piston means in opposition to each other, said driver including means on and rotatable with said shaft for controlling venting of said chamber means to control the pumping operation of said piston means, switch valve means in said fluid reservoir and connected between said driver and said first and second pump head means for alternately directing the actuating fluid under pressure to said first and second mentioned reciprocable pumping means, and feedback sensing means in said fluid reservoir and connected with and actuated by said first and second reciprocable pumping means for actuating said switch valve means when said first and second reciprocable pumping means have completed strokes of predetermined length.

2. A pumping apparatus comprising housing means providing a fluid reservoir, pump head means on said housing means including reciprocable pumping means, means in said fluid reservoir for delivering fluid under pressure from said fluid reservoir to said pump head means for actuating said reciprocable pumping means, valve means in said fluid reservoir and connected between said fluid delivering means and said pump head means for alternately directing the fluid under pressure from said delivering means to said pump head means and venting said pump head means, said fluid delivering means including body means providing pressure chamber means in said fluid reservoir having inlet and outlet ports, opposed piston means operable in said chamber means for pumping fluid therefrom, a rotatable shaft adjacent said piston means, and opposing cam means on said shaft and respectively engageable with said opposing piston means for actuating said opposing piston means in opposition to each other.

3. A fluid pumping apparatus comprising pump head means including relatively slow reciprocable large volume pumping means, and relatively high speed piston pumping means connected with said pump head means for delivering fluid under pressure, switch valve means connected between said piston pumping means and said reciprocable pumping means for directing said fluid under pressure for actuating said reciprocable pumping means, said relatively high speed piston pumping means including control means for accomplishing substantially shockless variable output pumping action. I

4. A pumping apparatus comprising pump head means including reciprocable pumping means, and piston pump means for delivering actuating fluid under pressure to said pump head means for actuating said reciprocable pumping means, said piston pump means including pumping chamber means and piston means reciprocable within said pumping chamber means, driven valve means separate from said piston means for controlling venting of said pumping chamber means for providing a variable substantially shockless output of said piston pump means, and means for adjusting said valve means for venting said chamber means at different positions of said piston means so as to vary the output of said piston pump means.

5. In a pump structure, first and second pump head means respectively including first and second fluid pressure operable reciprocable pumping means, control means for directing liquid under pressure from ,a liquid pressure source substantially instantaneously from one of said pumping means to the other of said pumping means when said one pumping means has completed a predetermined pumping stroke, and resiliently expandable reservoir means connected between said pressure source and said control means for accommodating any liquid delivered from the pressure source While said control means is operating so as to direct the liquid from one pump head means to the other.

6. In a pump structure, first and second spaced apart pump head means respectively including first and second fluid pressure operable reciprocable diaphragm pumping means, a manifold adapted to be connected with a source of actuating fluid under pressure, first and second spaced apart switch valve assemblies respectively located adjacent said first and second pump head means connected with said manifold and with said first and second pump head means, and connecting rod means interconnected with said first and second diaphragm means, a first toggle switch member pivotally disposed for movement about a predetermined axis between said first and second switch valve assemblies, first and second links respectively conmeeting said first toggle switch member and said first and second switch valve assemblies for actuating said switch valve assemblies upon movement of said first toggle switch member to and from opposite sides of a predetermined dead center position, a second pivotaliy mounted toggle switch member having one end pivotally connected to and actuated by said rod means and an opposite end located adjacent said first toggle switch member and traversing said axis, spring means connecting said last mentioned end of said second toggle switch member and said first toggle switch member for actuating said first toggle switch member and said switch valve assemblies for alternately directing fluid under pressure from said manifold to said first and second diaphragm pumping means.

References Cited in the file of this patent UNITED STATES PATENTS 326,545 Class et al Sept. 22, 1885 349,594 Johnson Sept. 21, 1886 588,296 Spencer Aug. 17, 1897 1,503,634 Bucherer Aug. 5, 1924 2,431,686 Deschamps Dec. 2, 1947 2,606,500 Schmidt Aug. 12, 1952 2,625,886 Browne Jan. 20, 1953 2,780,177 Hoenecke Feb. 5, 1957 2,842,068 Sundin July 8, 1958 2,843,045 Mashinter July 15, 1958 FOREIGN PATENTS 305,235 Great Britain of 1930 517,898 Belgium Mar. 14, 1953 

